Molding-core



l.. C. EVON.

MOLDING CORE.

APPLlcArloN FILED MAY l, 1919.

Patented Apr. 6, 1920.

.nu .m g P C i@ ITED STATES n'IIYEII OFFICE.

LOUIS C. EVON, 0F DETROIT, MICHIGAN, ASSIGNOR T0 SEARIGH'ILDOWNS MANUFAC- TURING C0., OF DETRGIT, MICHIGAN, CORIORATION OF MICHIGAN.

HOLDING-CORE.

Application filed May 1, 1919.

To all whom *it may concern.'

Be it known that I, Louis C. EvoN, a citizen of the United States, residing at Detroit, in the county of TWayne and State of Michigan, have invented certain new and useful Improvements in Molding-Cores, of which the following is a specification.

This invention relates to coreslfor use in casting, especially die casting. It has for its obj ect a collapsible core which is so constructed that it may be very quickly removed from the dies of the mold. One of the important novel features is a provision for employing the aid of mechanical advantage in separating the center core part from the other core parts to allow the core to collapse.

In casting, especially in casting aluminum, the aluminum sets very quickly and it also has a very high shrinkage. The result is that the core has to be very quickly removed or else the casting will shrink upon the core in such a way as to make it almost impossible to get it out. In the casting oic pistons, the wrist pin bearings are in the form of inturned projections which make it impossible to remove the core unless it is collapsed. It is, therefore, necessary to em ploy a collapsing core. I use a core made up of a number of segments with a tapering central segment which wedges in between the other segments to properly spread them out to their correct diameter. When the metal has been poured into the dies it sets very quickly, especially if it is aluminum, and begins to shrink upon the core, thereby making it very difiicult to remove this center wedge wit-hout some kind of a prying action. It prying action is furnished by some kind of a hand tool, it is quite liable to so disturb the parts as to injure the casting. I avoid these injuries to the casting and provide a quick and a very efficacious way ot removing the tapering centering element by the aid of a screw and bridge arrangement which will be described more 1n detail after the figures are described.

In the drawings,

Figure 1 is a vertical section of the dies and the core.

Fig. 2 is a plan view of the same.

Fig. 3 is a fragmentary perspective showing how the segments of the core go to-l gether.

Specification of Letters Patent.

ypear from Fig. 5.

Patented Apr. 6, 1920.

Serial No. 294,114.

Fig. 4 is a cross section taken on the line 4 4- of Fig. 1.

Fig. 5 is a view showing how the tapering centering element is taken out of the core.

Fig. 6 is a longitudinal section of the dies showing the core in elevation, taken on the line 6 6 of Fig. 2.

Fig. 7 is a cross section on the line 7-7 of Fig. 6.

The mold or dies comprise a pair of sections a and Z) which go together on the line 6 6 oi' Fig. 2 and may be held together by any suitable frame or mechanism, which need not here be shown. rlhe mold or dies are here shown for casting a piston, but it is obvious that the improvement may be used in connection with a great many other castings. The dies are recessed at c to re; ceive the pins CZ that are really the cores for the wrist pin bearings of the piston. The core segments are recessed at c to form the mold for the wrist pin bearings. rl`he core itself is made up of a plurality of segments which may vary in number, but which is here shown as iive (see Fig. 4). The central segment comprises in effect two segments joined by a central web This central segment is made on a taper, as will ap- This enables the central tapering section to be `forced down between the other segments which are complementarily tapered as shown in Fio'. 5, thereby spreading these out to their full diameter. The central tapering section passing diametrically from side to side of the core enables the other core segments to be tied to it by the tapering pins g (Fig. 4) which run each through a segment at each side of the central tapering segment and also through the central tapering element so that these two pins tie the i'i'our other elements to the central element and consequently tie all the elements together.

The stud it threaded at both ends screws into the top of the center tapering segment and passes through the plate z' which is held by screws to the top of the central tapering segment and into which are driven the Jfour dowel pins which serves to properly locate each segment with respect to the central tapering segment.

A, bridge or yoke 7c lits over the stud 7i and a nut Z runs on thev outer threads of the stud 7L and bears against the bridge or yoke f: through the interposed washer m. u is a renewable wooden handle that can be screwed into the end of the stud It. The ends of the yoke lc, as shown in Fig. 2, bear on all the four smaller segments of the core. Now obviously by screwing down on the nut Z, this will force the yoke ends against the small core segments and is bound to lift the center tapering core section upward` This will start the separation of the core segments with the aid of the powerful advantage of the screw. After they have been separated slightly the core section may be pulled out by the hand. 'Ihis is obviously a very great improvement over endeavoring to pry the core section out with some tool. Of course, before the sect-ion can be pried out in this way, the tapering pins g must be removed.

The core studs l are fastened pivotally to arms o provided with terminals formed into rolls to bear against the sides of the die so as to draw them out in the manner shown in Fig. 2.

After the central tapering core section has been lifted out, this allows the outside smaller core sections freedom to draw in toward the center and consequently there is no danger of their being caught in the fast shrinking casting. rIhey may then easily be lifted out by hand with the aid of the elbow-like handles p.

l/Vhat I claim is:

l. A molding core, having in combination, a plurality of collapsible parts including a spreading member, and means for starting the release ofthe member, comprising a bride or oke ada ted to bear on the other e y P ystart the spreading member.

2. A molding core, having in combination,

a plurality of sections including a central tapering section adapted to spread the outer sections, and means for starting the release of the central section including a screw secured to the central section, a bridge through which said screw passes having ends bearing against the outer sections, and a nut adapted to engage with the screw and bear upon the bridge to lift the central section with respect to the outer sections.

3. A molding core, having in combination, a plurality of sections including a central section, the outer sections being on either side of the central section, and one or more pins adapted to be passed through the outer sections and through the central section for tying the sections together.

el. A molding core, having in combination, a central tapering section, a plurality of outside sections von each side of the central tapering section, and pins Yrunning through the outer sections and through the central section to tie the same together.

A molding core, having in combination, a plurality of sections including a central section and outside segments, the latter provided with dowel pin holes, and .a plate on the central section provided with overhanging portions adapted to carry dowel pins to fit into the dowel holes in the outside sections to locate such section.

6. A molding core for a piston, comprising a central core section and smaller outside sections on the sides of the central sec-4 tions having recesses forming wrist pin bearings on the piston, said central section being withdrawable longitudinally to allow the outside sections to be drawn inward to clear the wrist pin bearings cast in the pistons,

In testimony whereof I afhx my signature.

LOUIS C. EVON. 

